Reactions of olefinic molecules in the presence of metal-containing catalysts to produce other olefinic molecules are known in the art as "disproportionation" or "metathesis" reactions. A typical olefin disproportionation process is illustrated by U.S. Pat. No. 3,261,879, issued July 19, 1966, to Banks, wherein two similar non-symmetrical molecules of an olefin react in the presence of certain catalysts to produce one olefin of a higher carbon number and one olefin of a lower carbon number such as, for example, propylene disproportionation to produce ethylene and butylenes.
A variation of this disproportionation process, is illustrated by the Netherlands Patent Application 6,514,985, published May 20, 1966, wherein, in one modification, molecules of two dissimilar symmetrical olefins are reacted to form two molecules of a single olefin product, e.g., ethylene and 2-butylene react to form propylene.
Another variation of the process, being conveniently termed "ring opening disproportionation" to distinguish it from other variations, is disclosed by British Patent Specification No. 1,163,657 of Phillips Petroleum Company, published Sept. 10, 1969, wherein a cyclic olefin and an acyclic olefin react to form a single product molecule. For example, ethylene reacts with cyclopentene by ring opening disproportionation to produce 1,6-heptadiene.
As used in this application, "disproportionation" or "metathesis" process means the conversion of olefinic hydrocarbons into similar olefinic hydrocarbons of higher and lower numbers of carbon atoms per molecule. Where the reactant comprises 1- or 2-olefins having relatively long chains, a mixture of products is obtained comprising primarily olefins having both a larger and a smaller number of carbon atoms than the feed olefin but also including other disproportionated products, for example, saturated hydrocarbons, and other converted and unconverted material. Such an operation is useful in many instances. For example, a more plentiful hydrocarbon can be converted to a less plentiful and therefore more valuable hydrocarbon. One instance occurs when the process of this invention is used to convert both higher and lower molecular weight olefins to olefins in the C.sub.10 -C.sub.16 range, a range of olefins especially suitable for the manufacture of detergents. Another instance of a disproportionation reaction having considerable value is the disproportionation of propylene to produce ethylene and butene.